Soybean red crown rot (RCR), caused by the soil-borne fungus Calonectria ilicicola, significantly reduces soybean yield and quality. A hypovirulent strain of C. ilicicola, designated UH2-1A, was obtained by repeated subculturing of the virulent strain UH2-1. UH2-1A exhibited significantly reduced pathogenicity after 20 and 40 subcultures, with RCR symptom scores of 0.8 and 1.0, respectively, compared to 3.0 and 4.0 for UH2-1. No differences in growth rate or direct antagonistic effects were observed between UH2-1A and UH2-1. Notably, incorporating UH2-1A into the UH2-1 inoculum mixture significantly reduced the RCR incidence at UH2-1A/UH2-1 ratios of >= 1.0 in greenhouse experiments. The suppressive effect of UH2-1A was also observed against four additional virulent C. ilicicola strains, suggesting broad control potential. These results highlight UH2-1A as a promising biological control agent for soybean RCR and provide an effective method for generating hypovirulent pathogen strains to control diseases caused by intraspecific pathogens.
The assessment of photosynthetic pigments is a reliable indicator for evaluating plant productivity and environmental stress. Therefore, developing an in-situ method for monitoring photosynthetic pigments is essential for effective tea crop management. Hyperspectral reflectance has been widely applied to assess vegetation properties, including pigment content, using portable spectroradiometers. However, the cost of these devices remains high and inaccessible for general use. This study evaluated the potential of an unmanned aerial vehicle (UAV)-mounted hyperspectral sensor incorporating a cost-effective, fingertip-sized spectrometer (C12880MA-10, Hamamatsu Photonics K.K.) to estimate chlorophyll and carotenoid content in tea leaves using the PROSPECT-D+SAIL model. Based on the ratio of performance to deviation (RPD), the proposed approach demonstrated effective performance in estimating both chlorophyll and carotenoid content, with RPD values exceeding 1.4.
This study examined the preferences of urban Chinese consumers for mung beans through a survey conducted in three major cities. Using the concept of food values and the best-worst scaling (BWS) approach, the findings highlight safety, nutrition, naturalness, and taste as key drivers of mung bean purchases. Latent class (LC) analysis further identified three distinct consumer segments: Class 1 placed the strongest emphasis on environment, followed by safety and nutrition; Class 2 prioritized safety, regardless of price; and Class 3 required both healthfulness (reflected in safety and nutrition) and good taste for a product to be selected.
Phytophthora blight, primarily caused by Phytophthora nicotianae, poses a significant threat to Helleborus production under warm and humid conditions. However, the tolerance levels of different Helleborus cultivars to this disease have not yet been compared. Thus, this study aimed to assess disease tolerance in the 17 major Helleborus cultivars available in Japan, all propagated via tissue culture to ensure genetic uniformity. The plants were inoculated with P. nicotianae, and the disease progression was monitored over 20 days. Our results revealed substantial variation in disease severity among the cultivars. The 'Petit doll' cultivars, particularly 'Petit doll Shiori,' exhibited strong and consistent tolerance, whereas the others, such as 'White sugar chiffon' and 'Mayuhiki,' showed high susceptibility. Some cultivars displayed delayed symptom development followed by rapid progression. In several cases, discrepancies were observed between root and foliar symptoms, indicating that above- and below-ground responses do not always correlate. This highlights the diversity of disease responses and the need for integrated evaluation methods when screening for disease tolerance. The tolerant cultivars identified in this study are valuable resources for breeding programs to improve resistance and ensure the sustainability of Helleborus production.
In this study, we aimed to determine a method for measuring soil matric potential using a simple soil moisture meter (SSMM) with a contact material, such as silt loam. Silt loam as a contact material ensured water continuity between the sensor of the SSMM and the soil, enabling it to function correctly. The SSMM indicator was consistent with measurements from a conventional soil water potential sensor; thus, the soil matric potential could be estimated across multiple fields with different soil types, with an RMSE accuracy of 61-203 kPa. These results demonstrate the potential of the SSMM to estimate soil matric potential below-50 kPa (above pF 2.7) and highlight its utility as a practical field-measuring instrument.
